The invention relates to a heat dissipation module, and in particular to a heat dissipation module capable of increasing the dissipation area and preventing reverse airflow.
As efficiency of electronic devices increase rapidly, heat dissipation modules have become essential components for the electronic devices. Electronic devices will become inefficient or burn out if the heat generated by the electronic device is not efficiently dissipated. Particularly, heat dissipation apparatuses are critical to microelectronic elements, such as integrated circuits. As integration increases and package technology improves, size of the ICs is reduced, and heat accumulated in the unit area thereof increases relatively. Thus, high efficiency heat dissipation modules are the object of constant research in the electronics industry.
Generally, ventilation, convection or heat dissipation in a heat generating system such as a server, a computer, an electronic mechanism or a power supply is facilitated by a heat dissipation apparatus, such as an axial flow fan, or a centrifugal fan. The heat dissipation apparatus can guide air flow to dissipate heat generated by the electronic devices to the environment for performing heat dissipation or air convection.
FIG. 1A is a schematic view of a conventional heat dissipation module. The conventional heat dissipation module 10 comprises a first blower 110 and a second blower 120. The first blower 110 and the second blower 120 are separated by a side wall 14 so that the airflow in the first blower 110 and the second blower 120 can be discharged through the outlet 111 and the outlet 121 of the first blower 110 and the second blower 120 respectively.
The heat dissipation module 10, however, is a plug-in module, and independent from the heat source. As shown in FIG. 1A, because the first blower 110 is disposed in front of the second blower 120, there is a space C existing in the first blower 110 near the second blower 120. The space C provides enough space for air to flow in reverse. When the first blower 110 operates, turbulent flow occurs at the space C in the first blower 110, which reduces the efficiency of the first blower 110 during operation.
Further, the length and the width of the airflow passage of the first blower 110 are different from the length and the width of the airflow passage of the second blower 120 such that the outlet 111 and the outlet 121 have different pressure. That is, the air pressure at the outlet 111 is much smaller than the air pressure at the outlet 121 when the blower 110 and the blower 120 are in operation. Thus, turbulent flow occurs at the border between the outlet 111 and the outlet 121 so that the dissipation efficiency of the heat dissipation module 10 is greatly affected.
Additionally, FIG. 1B illustrates the heat dissipation module 10 in FIG. 1A, in which one of the fans malfunctions. For example, when the second blower 120 malfunctions, only the first blower 110 operates so that air is only discharged through the outlet 111. Because the outlet 121 of the second blower 120 is directly communicated with the external environment, the air flows freely in and out through the outlet 121. Under this circumstance, the air flows in reverse into the second blower 120, such that the accumulation of hot air in the second blower 120 may affect the first dissipation apparatus 110. Thus, the entire dissipation efficiency of the heat dissipation module 10 is reduced.